CCR7 ligands, SLC/6Ckine/Exodus2/TCA4 and CK beta-11/MIP-3 beta/ELC, are chemoattractants for CD56(+)CD16(-) NK cells and late stage lymphoid progenitors

Two human CC chemokines, SLC/6Ckine/Exodus2/TCA4 and CK beta-11/MIP-3 beta/ ELC, are previously reported as efficacious chemoattractants for T- and B-c ells and dendritic cells. SLC and CK beta-11 share only 32% amino acid iden tity, but are Ligands for the same chemokine receptor, CCR7. In this study, we examined chemotactic activity of SLC and CK beta-11 for NK cells and ly mphoid progenitors in bone marrow and thymus. It was found that these two C CR7 ligands are chemoattractants for neonatal cord blood and adult peripher al blood NK cells and cell lines. SLC and CK beta-11 preferentially attract the CD56(+)CD16(-) NK cell subset over CD56(+)CD16(+) NK cells. SLC and CK beta-11 also demonstrate selective chemotactic activity on late stage CD34 (-)CD19(+)IgM(-) B-cell progenitors and CD4(+) and CD8(+) single-positive t hymocytes, but not early stage progenitors. It was noted that SLC is an eff icient desensitizer of CK beta-11-dependent MR cell chemotaxis, while CK be ta-11 is a weak desensitizer of SLC-dependent chemotaxis. Taken together, t hese results suggest that SLC and CK beta-11 have the potential to control trafficking of NK cell subsets and late stage lymphoid progenitors in bone marrow and thymus. (C) 1999 Academic Press.